通过SiC颗粒示踪法获得了焊丝填充对熔池表面流动的影响规律, 分析了不同的焊接工艺、焊丝填送模式和送丝角度对熔池表面波动行为及焊缝成形的影响。结果表明, 在激光自熔焊过程中, 熔池表面液态金属向后方及熔池另一侧流动, 熔池表面波动较剧烈, 焊缝表面出现凹陷缺陷; 在激光填丝焊过程中, 熔池表面金属全部表现为从前向后的快速流动, 熔池表面波动相对稳定, 焊缝表面成形良好。在激光填丝焊过程中, 焊丝的过渡模式对熔池表面稳定性有显著影响, 降低送丝角度有利于获得稳定的液桥过渡及减少焊缝气孔缺陷。

By the SiC particle tracer method, the effect rule of filler wire on the surface flow of molten pool is obtained, and the effects of different welding processes, wire feeding modes and wire feeding angles on the fluctuation behavior of the molten pool surface and weld formation are analyzed. The results show that, in the autogenous laser welding process, the liquid metal on the molten pool surface flows to the back and the other side of the molten pool, the molten pool surface fluctuates remarkably, and depression defects appear on the weld surface; in the laser welding process with filler wire, the molten pool surface metal flows rapidly from forward to backward, the molten pool surface is relatively stable, and the weld surface is well formed. In the process of laser welding with filler wire, the transition modes of filler wire have significant effects on the stability of the molten pool surface, and it is beneficial to obtaining a stable liquid bridge transition and reducing the weld hole defects by reducing the wire feeding angle.